The present invention relates to a sheet feeder having a sheet hopper and a sheet feed roller for delivering each one of the sheets stacked in the hopper to a predetermined location. The present invention also relates to an image forming device having the sheet feeder.
In a known sheet feeder used in a printer, the sheet in the uppermost position of a sheet stack in a sheet hopper is delivered in the specified feed direction by a sheet feed roller which is in contact with the uppermost sheet. In order to separate the uppermost sheet from the remaining sheets of the sheet stack, a corner pawl, a reverse rotation roller or a friction pad is available. However, these require a great deal of assembly work. For example, the corner pawl must be vertically movably attached to a side wall of a sheet cassette, the reverse rotation roller must be disposed below the sheet feed roller in driving connection with a drive source, and the friction pad must be pivotally movably provided while providing a constant contacting pressure with the sheet feed roller.